Rev. Cecil Williams, 83, and his wife, Janice Mirikitani, 71, have been the forces behind the legendary Glide Memorial Methodist Church in San Francisco for 50 years. They are now telling their story in Beyond the Possible (Harper One). Finishing each other's sentences, they chat with USA TODAY's Craig Wilson.

1. So, share your secret. Why does Glide thrive?

"Because we are still alive. Because we are always looking at how we might innovate. We are always open to possibilities," says Williams. "We embrace the contradictions. We invite the edge. We need it. The diversity. We invite in the madness," says Mirikitani. "That's what keeps us vital. It keeps us on our toes."

2. Are you surprised at Glide's success?

"I'm always surprised when I look at the measure of time. It doesn't seem like 50 years. It's wondrous what's been built here. When you look at the comprehensiveness of what we do, to have it happening," says Williams. "I'm taken aback. We've cried. We've fought. We almost divorced. It's been quite a journey," says Mirikitani.

3. Advice for first-timers on a Sunday morning?

"Get ready! Get ready to be excited. To move. To see something different. Make sure when you come to be open to all possibilities," says Williams. "There's a spirit here of getting things done. A sense of being loved. That's what lifts us up, and it's real," adds Mirikitani.

4. The biggest problem facing your congregation right now?

"Mental illness is one of the big issues now," says Mirikitani. "The poor have always been marginalized. The problems continue because many people still feel powerless."

5. Up for another 50 years? What's next?

"I'm going along as I have," says Williams. Adds Mirikitani, "I keep looking for new things to do. Poor people are still being exploited. There are reasons to continue. We started here, and we're going to stay here."